Oviductal fluids contain several enzymes that may be important in fertilization and early embryonic development. We have described the presence of divalent cation-dependant ATPase, protein kinase, phosphoprotein phosphatase, alkaline and acid phosphatase. The ATPase has been purified and antibodies against it have been prepared. This enzyme has been shown to be transferred from the secretory cells to the surface of the ovulated oocyte. The phosphatases and protein kinase have been partially purified. The protein kinase has many of the properties of a holoenzyme. Copurification experiments combined with studies of cation and pH depending indicate that the phosphatases are separate enzymes. Studies are now underway for the preparation of antibodies to these enzymes to better understand their functions in oviductal fluids.